Chaotic Tracer Transport: a Modeling Study of the Alboran Sea

The Alboran Sea, at the interface of the Atlantic and Mediterranean, has large regions of chaotic flow-- motion characterized by exponential stretching and folding of fluid parcels. The surface flow usually contains two anticyclonic gyres to the south of the Atlantic Jet, which carries Atlantic Water into the region. This work studies the near-surface transport between the Atlantic Jet and the gyres in two dimensions using the MITgcm. I use Lagrangian methods to define gyre boundaries by manifolds of the fluid motion, and quantify chaotic transport using lobe dynamics, avoiding spurious fluxes caused by the gyre moving across its mean boundaries. The rates of transport by chaotic advection, parameterized turbulence, and Ekman pumping are compared and correlated with the forcing applied at the open boundaries and from the atmosphere. Seasonal budgets of slainity and vorticity in each gyre are discussed.